This weekend I tried - for the fifth time now - to use the self-service checkouts at a well-known store. I've used them at Woolworths, Kmart and Target previously, this time I was in a Big W store.
if you've used them before, then you probably know the drill.

You come up to the checkouts, and spot a huge queue for one of the few hapless operators floating amidst a sea of un-manned isles. Whereas off to one side there's a set of self-service checkouts, with a sprinkling of customers working their way through. You figure 'what the hell', and you give it a shot.

Then it goes something like this:

Press Start.

Scan first item. Smile smugly as the price comes up, and place item in a bag, as directed.

Scan second item. Think to self 'This is a piece of cake!' as you place it beside number 1.

Frown, as 'Computer says no'. Apparently you've removed an item from the bag. look down at two items, behaving themselves within said bag.

Scan item 3, then growl as the computer tells you to fetch help.

Wave at the overworked assistant trying to help the old lady who's started throttling her own self-service checkout in an explosive fit of undisguised frustration. Wait till she can break free, amusing yourself by counting the people who queued for a human as they march through one by one.

When assistant arrives, complain that you didn't remove anything. The assistant knows this of course and doesn't even bother to check (she's used to the computers and their continuous paranoid delusion on the contents of bags). She scans a card, presses some buttons, and you're back to item 3.

Scan item 3, 4, and 5. Convince yourself that apart from one small hiccup, this isn't going too bad after all.

Scan item 6, remove full bag and place item 6 in the new bag. Feel that creeping sense of dread as the computer, finally proved correct in its theory that you're trying to steal, gleefully shouts again that you've removed items from the bagging area and demands staff come immediately.

Swear never to repeat this exercise again.

It happened to me, and it was happening to just about everyone around me - the hapless assistant was dancing from one machine to another, desperately trying to guard both the machinery and the customers from a complete nervous breakdown.

It's not rocket science, and this is exactly what User Centred Design is there to protect against. Design this around customers and it would work in a completely different way. So just in case someone is listening, here are my top five tips for improving self-service checkouts:

Don't assume the customer is a thief. The only reason I can see for measuring the bags is to validate that they haven't slipped something extra in there to steal it. Let's be honest, I could slip something into my pocket at any point whilst walking around the store. I don't, because firstly store security might well be observing me, and secondly because I'm honest. Both of those are just as true at the checkout, and there are extra cameras and staff to observe clearly. Why treat all honest customers like crooks?

Explain the process up-front. Most of these systems don't tell you key bits of information, such as the fact that you have to place items in a bag so they can be measured, and that you can't remove a bag till you press a certain button.

Provide more space - I know they want to cram in as many of these devices as possible, but giving people a tiny space to try and juggle armfuls of goods whilst balancing bags for weighing and removing at the right time is insane. Three times now I've had the 'item removed from bagging area' message just because something shifted slightly in the bag and some weight shifted off the scales.

Provide more assistance - when something goes wrong, there's very little help in here. Basically it's like a car that is driving fine one moment, then explodes into flames the next with no warning or chance to pull over. Give the user some hint of what to do, and some ability to avoid the embarrassing "Miss, miss, I've broken it again..." plaintiff call for help.

Make me feel good about doing it. And for me, this is key. When I check in at an airport it knows my name, it welcomes me, and makes the choices simple, it makes me feel valued as a customer, and then it sends me on my merry way. When I self-service in a store, it assumes I am a criminal, it doesn't welcome me or know me from Adam (even though I might have a store card and shop there regularly), it regularly spits the dummy and demands I go get help, and does absolutely nothing to make me feel valued.

Right now, I'm only using these systems at all because firstly I'm a geek and I want to see how they work, but secondly because these stores are starting to reduce staffing levels on the operated checkouts in order to force customers through these channels. And already I'm beginning to consider switching to stores that don't force me into a terrible user experience, just because it saves them some bucks.

I went to complain at Big W, and was told that they received very few complaints. When you see the red faced annoyed customers skulking off, I can't imagine why. But it's time to start.